Oil circulation device in a sewing machine



April 23, 1968 1.. BONO OIL CIRbULATION DEVICE IN A SEWING MACHINE Original Filed Feb. 19, 1964 2 Sheets-Sheet l FIG1 April 23, 1968 L, BONO 3,379,152

OIL CIRCULATION DEVICE IN A SEWING MACHINE Original Filed Feb. 19, 1964 ZSheets-Sheet :1

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F IG. 6 -1122) United States Patent .TWMW

ABSTRACT OF THE DESCLOSURE An oil pumping means in a sewing machine, including an oil piston pump whose piston is radially cut away for a portion of its length and which is reciprocably driven along a cylinder axis and also rotatably oscillated about said axis by means of an eccentric driving connection which drives piston jointly with the hook shaft of the machine, the piston cut away portion serving to alternately close and open radially opposite oil ports in the cylinder.

This application is a continuation of Ser. No. 345,963, filed Feb. 19, 1964, and now abandoned.

The present invention refers to an oil circulation device in sewing machines.

The principal purpose of this invention is that of providing a simple and effective device for lubricating satisfactorily sewing machines running at high speeds. Another purpose of this invention is that of providing a device which would not occupy much space in the limited interior of a sewing machine. The device in question mainly consists of a pump having a piston moving axially in order to pump the lubricant and which possesses an oscillatory movement around its own axis so as to close alternatively the suction and delivery openings of the pump.

A further characteristic of the device in question is that of deriving the movement of the piston from a mechanical member of the machine already existing, which may be, for instance, the shaft of the hooks of a double chain stitch machine.

Said piston has its own free end formed by a radially truncated portion so that during the oscillatory move ment while with the lowered part it opens, for instance, the suction opening, with the cylindrical part it closes the delivery opening, and vice versa, when the lowered part opens the delivery opening, the cylindrical part closes the suction opening. From the purposes and the above mentioned characteristics of the invention and from those which will ensue from the detailed description of the invention with reference to the enclosed figures, given on an illustrative basis but not limited thereto. The importance of the invention will appear clear.

FIGURE 1 is a vertical section passing through the shaft of the hooks of the machine base;

FIGURE 2 is a section according to line IIII of FIGURE 1;

FIGURES 3 and 4 illustrate positions of the piston in its different moments;

FIGURE 5 represents a cutaway detail of the cylindrical piston unit;

FIGURE 6 represents schematically the cooling circuit taken as an illustrative example.

In the base 1 of the machine is keyed a bushing 5 supporting the shaft 2. The hooks '3 and 3 of the shaft 2 cooperate with the respective needles 4 and 4' fixed by the clamp 6 to the needle bar 7 for the formation of the double chain stitch. Said needle bar receives the alternating movements which are necessary for the stitch formation through known means which are not illustrated here.

In synchronism with the alternating movements of the needle bar 7, the hooks 3 and 3' must be submitted to a movement resulting from a movement of alternating translation along the axis K of the shaft 2 and from a movement of alternating oscillation around said axis. In the sewing machine illustrated by way of example in the enclosed figures, the shaft 2 is driven by an arrangement similar to that disclosed in United States Patent No. 3,112,720 whereby said shaft receives the above mentioned movements from an eccentric 8 fixed by means of screw 23 to the shaft 9 rotating perpendicularly to said shaft 2. The eccentric 8 is locked by a body 10 which, from opposite parts, carries the coaxial holes 11 and 12 parallel to the shaft 2 and eccentric with respect to the axis K of said shaft. In the holes 11 and 12 are pivoted pins 13 and 14 respectively of two small crank arms 15 and 16 whose heads 17 and 18 respectively are constituted by pivoted pins, coaxially between them and cccentrically with respect to the axis K, on two sleeves 19 and 2%) respectively which are rigidly connected to each other by bridge element 21, said sleeves 19 and 2t) and element 21 forming a bridge assembly which is rigidly connected to a shaft 2 by means of set screw 22 whereby the bridge assembly and shaft 2 are all driven together. Eccentric 8 transmits to said body 10 oscillations whose component in the direction x is transformed by the small crank arms 15' and 16 into movements of alternating oscillations of the shaft 2 around its own axis K and whose component in the direction y is directly transmitted to the shaft 2 which performs movements of a1- ternating translation in the direction of its own axis K. In fact, the body 10 is adjacent to the small crank arms 15 and 16 and these is their turn are adjacent to the sleeves 19 and respectively, so that the body 10 and the shaft 2 are movable in said direction The running of the double chain stitch machines generally occurs at a considerably high speed, making more than 5,000 stitches per minute.

The base 1 of the machine is closed in the lower part, in order that the shaft 2 and the known fabric feeding members, which receive the movement from said shaft 9 and which are not shown here, may be immersed in the oil. However, due to the high speed, the quantity of oil contained within the base 1 is not sufficient in dispersing the heat which has been produced and it is necessary to create a forced circulation of the oil through a special cooling circuit. The present invention exploits said combined movement of the shaft 2 so as to obtain a pumpa ing effect of the oil through said circuit.

In the disclosed embodiment this is realized by providing a pin 24 rigidly extending from sleeve 20 (FIGURES 1 and 5), said pin being coaxial with and integrally rnovable togethcr with shaft 2. Pin 24 includes an end portion 25 which is defined on one side by a lengthwise extension of the cyiindrical surface of pin 24- and on the other side by a radially shortened surface relative to the left hand cylindrical portion of said pins so as to provide a radially lower or shortened surface 26, this radial truncation providing a space between surface 26 and internal wall 28 of bushing 29. Bushing 29 comprises a pump cylinder for pin 24- which comprises a piston slidable within said cylinder as well as a stub shaft for one end of the bridge assembly.

Bushing 29 is fixed in a hole 30 provided in the base 1 of the machine by means of the screw 31. Said bushing has a portion 32 of a smaller diameter and a portion 33 of a greater diameter, which portions are adjacent and coaxial. A hole 30 has two portions 34 and 35 with different diameters to constitute the seats for the portions 32 and 33 of said bushing. The portion 32 of bushing 29 has two radial holes 36 and 37 in diametrically opposite positions and which lead towards the two spaces 38 and 39 respectively. The spaces 31 and 39 define two chambers which are closed towards the exterior of the machine by the radial surface 41 separating the two portions 32 and 33 of the bushing 29 and which communicate with the interior of the machine through the holes 42 and 43 respectively, In said holes 42 and 43 are inserted the unions 44 and 45 from which start the tubes 46 and 47.

The tube 47 has an end opening within the base 1 and the tube 46 opens into a heat exchanger 48 (FIGURE 6) to which the lubricating oil arrives through a tube 49 fixed to base 1 and through a filter 51.

Towards the exterior of the machine, bushing 29 is closed by a cap 52 fixed by means of the screw 53. As explained above, bushing 29 is a cylinder of a pump casing, while the pin 24 works as a piston.

The seal of the pump casing is ensured by means of two elastic rings 54 and 55 which, arranged within circumferential grooves provided on the portions 32 and 33 of bushing 29, are compressed against the portions 34 and 35 of the hole 3% of the base 1.

The working of the pump is as follows: When the shaft 2 moves in the direction of the arrow y (FIGURE 4), the piston 24 places itself in such a position as to close with the cylindrical part of the end 25 the opening of the hole 37 and to open, by means of the truncated portion 26, the opening of the hole 36. When the shaft 2 moves in a direction opposite to that indicated by the arrow y (FIG- URE 3), the piston 24 places itself in such a position as to close with said cylindrical part the opening of the hole 36 and to open, through the truncated portion 26, the opening of the hole 37. As a consequence of this, during the displacements of the piston 24 in the direction of the arrow y, the oil is drawn through the exchanger 48 and during the displacements of the piston in the opposite direction the oil is forced through the hole 3'7 and then, through the tube 47, to the base 1. It is, therefore, seen that the truncated end portion alternately serves as a close means for the respective ports 36 and 37.

What is clamed is:

1. A sewing machine, comprising: a sewing needle, a hook, a hook shaft, said hook being connected to said shaft and being associated with said needle for forming stitches in a fabric which is being sewn, drive means including a hook shaft for reciprocating said hook along an axis and for oscillating said hook about said axis, a pump means for circulating lubricating oil and comprising a bushing having a cylinder bore therein, a piston member mounted in said cylinder bore for reciprocating movement along and for oscillating movement about the axis of said cylinder bore, said drive means being drivingly connected to said piston member whereby said drive means drives said piston member jointly with said hook and in accordance with the reciprocating and oscillating movements thereof; said cylinder bore including an inlet and an outlet port opening radially into said bore, closure cans responsive to the oscillatory movements of said piston member to alternately open one of said ports while closing the other, said closure means being responsive to the reciprocating movements of said piston member to reverse the opening and closing of said ports during respective axial strokes of said piston member.

2. A sewing machine, comprising: a sewing needle, a book, a hook shaft, said hook being connected to said shaft and being associated with said needle for forming stitches in a fabric which is being sewn, drive means including a hook shaft for reciprocating said hook along an axis and for oscillating said hook about said axis, a pump means for circulating lubricating oil and comprising a bushing having a cylinder bore therein, a piston member mounted in said cylinder bore for reciprocating movement along and for oscillating movement about the of said cylinder bore, said drive means being drivingly connected to said piston member whereby said drive means drives said piston member jointly with said hook and in accordance with the reciprocating and oscillating movements thereof; said drive means including a bridge means rigidly mounted to and between said hook shaft and said piston member, said shaft and piston member respectively extending coaxially from opposite sides of said bridge means, means for reciprocating said bridge means along the axis of said shaft and for oscillating it about said axis.

3. The sewing machine of claim 2, said piston member constituting a stub shaft for said bridge means and said cylinder constituting a bushing for said stub shaft.

4. The sewing machine of claim 1, said piston member comprising a cylindrical lengthwise portion axially a joining a radially truncated portion, a lengthwise extension of the surface of said cylindrical portion, a surface of lesser radial height than the radius of said cylindrical portion, said truncated portion being peripherally defined on one side by said lengthwise extension of the surface of said cylindrical portion and on the other side by said surface which is of lesser radial height than the radius of said cylindrical portion, said inlet and outlet ports being circumferentially displaced relative to each other along said cylinder bore, said truncated portion constituting said closure means with said one side thereof sliding against the wall of said cylinder bore and thereby close off one of said ports while simultaneously the said other side thereof is radially spaced away from the wall of said bore and thereby opens the other of said ports.

5'. The sewing machine of claim 4, including an oil cooling system having opposite inlet and outlet sides, said inlet and outlet ports being respectively connected to said opposite sides of said oil cooling system.

6. The sewing machine of claim 3, said means for reciprocating and for oscillating said body comprising a rotary drive shaft extending perpendicularly to the axis of said hook shaft, an eccentric mounted on said drive shaft for rotation therewith, movement translation means connecting said eccentric to said bridge means whereby rotation of said eccentric is translated into reciprocatory and oscillatory movement of said bridge means relative to the axis of said hook shaft.

References Cited i UNITED STATES PATENTS 2,998,787 9/1961 Pollmeier 112-256 X 3,060,877 10/1962 Ketterer 112-256 3,112,720 12/1963 Bono 112200 JORDAN FRANKLIN, Primary Examiner.

GEORGE KRIZMANICH, Assistant Examiner, 

